I have built a WCF Data (oData) service that is using dotConnect for Ora provider, version 5.70.190.0. When I execute a query to a single entity, selecting up to 8 properties, all is well. However, if I add just one more property/column to the list of selects I get the following exception (the type of the newly added property does not seem to make any difference) :

ArgumentNullException: Value cannot be null.Parameter name: value

and here is the stack trace:

at System.Data.Services.WebUtil.CheckArgumentNull[T](T value, String parameterName)
at System.Data.Services.Internal.ProjectedWrapper.set_PropertyNameList(String value)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)
at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()
at System.Data.Services.Internal.ProjectedWrapper.EnumeratorWrapper.MoveNext()
at System.Data.Services.DataService`1.SerializeResponseBody(RequestDescription description, IDataService dataService)
at System.Data.Services.DataService`1.HandleNonBatchRequest(RequestDescription description)
at System.Data.Services.DataService`1.HandleRequest()

I saw forums that mention similar problems, but it was recommended that the users upgrade and I am already using the latest version of the dotConnect for Ora.

Does anyone have any idea where I need to look at?
Is this a known issue?

It appears that the length of the URL is in play here - if I have it under around 180 characters it works, if it is higher than that, not so much.

Please put the following line in the constructor of your context (the Devart.Data.Oracle.Entity.OracleEntityProviderServices class is defined in the %ProgramFiles%\Devart\dotConnect\Oracle\Entity\EF4\Devart.Data.Oracle.Entity.dll assembly):